Micro-vials

ABSTRACT

A simple, low cost, efficient and stable micro-vial configuration for handling micro-volume of sample fluids. The interior wall geometry of the inventive vial is designed to include several axial sections of various interior diameters to provide a range of functionalities to address various design considerations. The interior wall defined in the vial has a cylindrical sample section, a wider cylindrical alignment section, a tapered or conical guide section, and a relatively large cylindrical body section, arranged in sequence in that order along the center axis of the vial. The sample section is designed to hold a small volume of a sample fluid, and to receive the tip end of a capillary tube. The alignment section has a larger diameter than the sample section, designed to receive a cylindrical support that coaxially supports the relatively fragile capillary tube. The tip of the capillary tube dips into the micro-volume of sample fluid held in the sample section. The conical section functions to guide the capillary tube and the support tube into the alignment section and the tip of the capillary tube into the sample section. The body section has the largest diameter, for holding additional fluid if desired.

PRIORITY CLAIM

This application claims the priority of U.S. Provisional PatentApplication No. 61/838,791 filed on Jun. 24, 2013; this application isalso a continuation of U.S. Patent Application No. 29/458,922 filed onJun. 24, 2013, which are fully incorporated by reference as if fully setforth herein. All publications noted below are fully incorporated byreference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to receptacles for holding fluid forbio-analysis, and more particularly to vials for holding small volumesof fluids.

2. Description of Related Art

DNA sequencing is a type of bio-analysis, involving the process ofdetermining the precise order of nucleotides within a DNA molecule. Itincludes any method or technology that is used to determine the order ofthe four bases—adenine, guanine, cytosine, and thymine—in a strand ofDNA. The advent of rapid DNA sequencing methods has greatly acceleratedbiological and medical research and discovery.

Knowledge of DNA sequences has become indispensable for basic biologicalresearch, and in numerous applied fields such as diagnostic,biotechnology, forensic biology, and biological systematics. The rapidspeed of sequencing attained with modern DNA sequencing technology hasbeen instrumental in the sequencing of complete DNA sequences, orgenomes of numerous types and species of life, including the humangenome and other complete DNA sequences of many animal, plant, andmicrobial species.

Next-generation sequencing (NGS) has revolutionized the geneticlandscape, It is a lengthy, labor-intensive process that yields resultsnever before achieved, As a result, it is imperative that the quality ofthe sample be evaluated from the start, as most NGS sample preparationprotocols require PCR amplification to generate DNA libraries prior tosequencing.

The likelihood of artifact generation could contribute to bias,affecting the potential results. High sensitivity DNA analysis has beenoptimized with the improved capillary gel electrophoresis detectionsystems developed by the assignee of the present invention, &Optic, Inc.(see, U.S. Patent Application Publication Nos. US2011/0253540A1 and2012/0168312A1; and, for example, the Qsep100 instrument developed byBiOptic, Inc.). Improved sensitivity allows the numbers of library PCRcycles to be reduced, removing amplification bias and significantlyimproving the quality of NGS data with increased accuracy.

Since relatively large volumes (e.g., in the order of 20 to 40micro-liters) of PCR products are necessary/needed to be used insequencing type instruments, and the sequencing sample preparationprocess is costly, preferably a small volume of PCR product is sampledfor screening quickly (e.g., through gel-electrophoresis or capillaryelectrophoresis) to make sure there is enough PCR product present(detected) in the PCR products before proceeding with the fullsequencing process (DNA analysis). This involves injecting a smallvolume of sample PCR product into the tip of a capillary tube, to allowthe sample to undergo electrophoresis through the capillary tube. It isdesired to sample as small a volume of PCR product as possible, so as toleave more PCR products available for subsequent sequencing.

It has always been a challenge in the field to try to contain a smallvolume of fluid in micro volume in the order of several micro-liters ina receptacle, and in particular in a manner to provide access to sampleby a capillary tube.

SUMMARY OF THE INVENTION

The present invention provides a simple, low cost, efficient and stablemicro-vial configuration for handling micro-volume of sample fluids,which overcomes the drawbacks of the prior art. Accordingly to thepresent invention, the internal wall geometry of the inventive vial isdesigned to include several axial sections of various interior diametersto provide a range of functionalities to address various designconsiderations. The interior wall defined in the vial has a cylindricalsample section, a wider cylindrical alignment section, a tapered orconical guide section, and a relatively large cylindrical body section,arranged in sequence in that order along the center axis of the vial.

The sample section has the smallest diameter of all the sections,designed to hold a small volume of a sample fluid (e.g., in the order ofless than 5 micro-liters, preferably 1 to 2 micro liters), and toreceive the tip end of a capillary tube. The alignment section has alarger diameter than the sample section, designed to receive acylindrical support that coaxially supports the relatively fragilecapillary tube. The support may be a metal tube, which extends from acapillary cartridge and functions as a tube-shaped electrode for suchcartridge. The capillary tube is threaded through the bore of thesupport tube, and the tip of the capillary tube extends beyond and isexposed from the end of the support tube. The tip of the capillary tubedips into the micro-volume of sample fluid held in the sample section.The conical section functions to guide the capillary tube and thesupport tube into the alignment section and the tip of the capillarytube into the sample section. The body section has the largest diameter.The vial thus has the capacity to hold a relatively large volume offluid, which can fill the body section.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and advantages of theinvention, as well as the preferred mode of use, reference should bemade to the following detailed description read in conjunction with theaccompanying drawings. In the following drawings, like referencenumerals designate like or similar parts throughout the drawings.

FIG. 1 is a perspective view of a strip of micro-vials in accordancewith one embodiment of the present invention;

FIG. 2 is a front view thereof (the rear view is a mirror image of thefront view);

FIG. 3 is a right side view thereof (the left side view is a mirrorimage of the right side view);

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and

FIG. 6 is a sectional view of a micro-vial taken along line 6-6 in FIG.4, showing interior structure, wherein each micro-vial has a similarinterior structure.

FIG. 7 is a perspective view of a strip of micro-vials with broken linesdepicting a strip of micro-vials of indefinite number of vials, inaccordance with one embodiment of the present invention (i.e., theinventive concept is not limited to the specific number of micro-vialslink together).

FIG. 8 is a front view thereof (the rear view is a mirror image of thefront view);

FIG. 9 is a right side view thereof (the left side view is a mirrorimage of the right side view);

FIG. 10 is a top plan view thereof;

FIG. 11 is a bottom plan view thereof; and

FIG. 12 is a sectional view of a micro-vial taken along line 12-12 inFIG. 10, showing interior structure, wherein each micro-vial has asimilar interior structure.

FIG. 13 schematically illustrates access of the micro-vials by anexternal device.

FIG. 14 is an enlarged view of the access of sample solution in amicro-vial.

FIG. 15 is a pictorial view showing access of sample solution in asingle micro-vial.

FIG. 16 is a top view of a strip of micro-vials, providing dimensions inaccordance with one embodiment of the present invention.

FIG. 17 is a side view of the strip of FIG. 16, providing additionaldimensions, in accordance with one embodiment of the present invention.

FIG. 18 is a sectional view taken along line A-A in FIG. 17, providingadditional dimensions, in accordance with one embodiment of the presentinvention.

FIG. 19 is another sectional view taken along line A-A in FIG. 17,providing additional dimensions, in accordance with one embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention is described below in reference to various embodimentswith reference to the figures. While this invention is described interms of the best mode for achieving this invention's objectives, itwill be appreciated by those skilled in the art that variations may beaccomplished in view of these teachings without deviating from thespirit or scope of the invention.

The inventive micro-vial is described in connection with the embodimentof sample injection and detection technique in bio-analysis,particularly micro-volume sample injection, separation and detectionthrough a micro-capillary channel, and more particularly a capillarytube supported in a gel capillary cartridge (e.g., developed by BiOptic,Inc.). The inventive micro-vial is especially useful for pre-screeningof PCR DNA products prior to Next Generation Sequencing applications.The inventive micro-vial can be adapted for use with other bio-analysistools, instruments and systems, in connection with other bio-analysisprocesses, which is well within the scope and spirit of the presentinvention.

The present invention provides a simple, low cost, efficient and stablemicro-vial configuration for handling micro-volume of sample fluids,e.g., for injection into a capillary column for bio-separation (e.g.,capillary electrophoresis for detection of PCR products (i.e., DNAsample)).

Referring to the embodiment shown in FIGS. 1-6, the micro volume vials10 can be configured in a strip 12 of N vials (wherein N is at least 1,but can be 8, 12, or any desired number). Referring to FIGS. 7-12, analternate embodiment is shown with broken lines to depict a strip 12′having at least two vials 10, but the number of vials may be indefinite,or of any number. Further, instead of a strip of a plurality of vials10, it is well within the present invention to configure separate singlevials 10 (see, e.g., FIG. 15, depicting a single vial 10). Further,instead of strips, the vials 10 may be defined as wells in a block orplate (i.e., a 96-well micro-titer plate having wells defined with theinterior wall geometry of the vial 10 disclosed here).

Specifically, adjacent vials are connected at the opening area by a tap14. A handle 19 is provided at each end of the strip 12. In oneembodiment, the center spacing between vials may be configured tocorrespond to the format of an industry standard 96-well (8×12)micro-titer plate. Several strips 12 of vials may be assembled to form atray of wells, e.g., resembling a 96-well titer plate, by using anappropriate holder or bracket (not shown).

Referring to the sectional views in FIGS. 6 and 12, the vial 10 has anexternal geometry which is not critical to the function of micro-volumefluid handling. In this regards, the vial 10 may be configured with arelatively large external body (e.g., a block having interior wallsdefining the interior wall geometry of the vial) for easier handling bya user. Accordingly to the present invention, the internal wall geometryof each vial 10 is designed to include several axial sections of variousinterior diameters to provide a range of functionalities to addressvarious design considerations. Referring also to the pictorial FIG. 15,the interior wall defined in the vial 10 has a cylindrical samplesection 20, a cylindrical alignment section 22, a tapered or conicalsection 24, and a cylindrical body section 26, arranged in sequence inthat order along the center axis 18 of the vial.

The section 20 has a cylindrical section with a bottom, and has thesmallest diameter of all the sections, designed to hold a small volumeof a sample fluid 30 (e.g., in the order of less than 5 micro-liters,preferably 1 to 2 micro liters), and to receive the tip end of acapillary tube 32 (e.g., about 0.350-400 mm overall external diameter,including cladding or protective coating on the silica capillary tube32).

The alignment section 22 has a larger diameter than section 20, designedto receive a cylindrical support 34 that coaxially supports therelatively fragile capillary tube 32. The support may be a metal tube(e.g., about 1 mm outside diameter, with a bore having an inner diameterof about 0.5 mm internal diameter to receive the capillary tube 32),which extends from a capillary cartridge 38 and functions as atube-shaped cathode 34 for such cartridge 28, as shown in FIG. 15 (seeBiOptic's capillary cartridge and analysis system discussed in U.S.Patent Application Publication Nos. US2011/0253540A1 and2012/0168312A1). The capillary tube 32 is threaded through the supporttube 34, and the tip of the capillary tube 32 extends beyond and isexposed from the end of the support tube 34. As shown in FIG. 15, thetip of the capillary tube 32 dips into the sample fluid in section 20.

The conical section 24 provides a tapered wall surface to guide thecapillary tube 32 and the support tube 34 into the alignment section 22and the tip of the capillary tube 32 into the section 20.

The body section 26 has an opening, and the largest diameter of the wallsections. The vial 10 thus has the capacity to hold a relatively largevolume of fluid, which can fill the body section 26.

A mineral oil 36 may be provided to fill the space above the samplefluid in the section 20, to prevent evaporation of the small volume ofsample fluid. The mineral oil 36 may fill the alignment section 22and/or the conical section 24 and/or the body section 26.

Referring to FIGS. 16-19, exemplary dimensions of a strip 12 of vials 10are provided, in accordance with one embodiment of the presentinvention. All dimensions shown in FIGS. 16-19 are in mm unit, unlessotherwise stated.

The above described micro-vials 10 and strips 12 may be made ofmaterials including glass, metal, plastic, rubber, silicon, etc.,preferably of a chemically inert material that is inert to reacting withthe fluid intended to be held in the vials 10. The vials 10 and/orstrips 12 may be formed by etching (e.g., of a semiconductor materialsuch as a silicon substrate), stamping (e.g., of a metal or plastic), ormolding (e.g., plastic or rubber injection molding). Further, the vials10 and strip 12 may be made of different materials, which may be fusedtogether to form the strip 12. The wall structure of the vials may bemade of a certain material and the interior wall of the vials 10 may belined with a chemically inert material.

Using the inventive vial for handling a micro volume of sample fluid, itis possible to develop bio-analysis systems that are significantly smallin overall size (see, e.g., BiOptic's Qsep 100 instrument).Miniaturization of analytical instrumentation has many advantages overconventional systems and techniques. These advantages include improveddata precision and reproducibility, short analysis times, minimal sampleconsumption, improved automation and integration of complex workflows.

In one embodiment, an injection-molded vial 10 can accommodate a smallvolume of 1 to 2 micro-liters (e.g., of PCR DNA Sample to be injectedelectro-kinetically using Capillary Gel Electrophoresis (CGE) forpre-screening and quality control (qualitative and quantitative). Themicro-vials are injection molded in strips of 8-vials or 12-vials andcan be directly inserted inside the BiOptic's CGE system (Qsep100)Sample Tray to interface the Pen-Shaped Gel-Cartridge for sample intakethrough the automated sample tray. Reference is made to BiOptic'scapillary cartridge and analysis system discussed in U.S. PatentApplication Publication Nos. US2011/0253540A1 and 2012/0168312A1).

According to the micro-vial design geometry of the present invention, itfacilitates sample injection in micro-liter volume of 1 to 2micro-liters. The alignment section 22 of the vial 10 allows thegel-cartridge electrode (cathode tube 34 in FIG. 15) with supportedcapillary tube 32 to be inserted and aligned accurately for sampleintake at the sample holding section 20.

The access of sample held in the vial 10 by a cartridge 38 isschematically shown in FIGS. 13, 14 and 15. Referring to BiOptic'sQsep100 DNA analyzer, the cartridge 38 is supported on a stand 50(schematically shown in FIG. 13), and a robotic mechanism 52(schematically shown in FIG. 13) moves the sample tray supporting thevials 10 relative to the tip of the capillary tube 32 supported in thecartridge 38. The cathode tube 34 (which coaxially supports thecapillary tube 32) in the cartridge 38 may be aligned automatically bythe sample tray mechanism, with the conical tapered section 24 of thevial 10 guiding entry of cathode tube 34 inside the alignment section22, which has an internal diameter (e.g., 1.75 mm) that is close to theoutside diameter of the cathode tube 34 (1 mm). Referring to FIGS. 14and 15, as the cathode tube 34 is further inserted inside the vial 10,the tip of the capillary tube 32 is guided and aligned to ensure contactwith the test or sample solution 30 (e.g., DNA sample).

One micro-liter of test solution can be placed in the sample section 20inside the vial 10 by using, for example, a standard handheld pipette.Since small air-bubbles could be introduced during sample deposition bythe pipette, it is recommended to spin (centrifuge) the vial 10 (e.g.,the entire strips 12 before further processing (in much the same way astandard 96-well microtiter plate is centrifuged). It is alsorecommended to apply a small amount of mineral oil to prevent sampleevaporation and facilitate multiple consecutive sample injections.

The vials 10 are designed to be single unit, or in 8 and/or 12-strips,or could be molded to be 96-vial or 384-vial format. The vials 10 can beused with other capillary electrophoresis, HPLC or micro-fluidic typeproducts (from different manufacturers) that have capillary basedcartridge, in which the capillary is supported by a metal, plastic,ceramic or other outside jacket/electrode.

In Summary, the inventive micro-vial achieve one or more of thefollowing advantages:

The inventive micro-vial allows handling of 1 to 2 micro-liter volume ofsample (e.g., PCR DNA sample) to be allocated inside the vial to beinterfaced with a capillary based cartridge for automated sampleinjection.

By applying a drop of mineral oil over the 1 to 2 micro-liters of sampleinside the micro-vial, o ne can do multiple sample injections(electro-kinetically) into the pen-shaped gel-cartridge. The mineral oilprevents sample evaporation, and due to conductive properties, it alsofacilitates multiple injections.

The inventive strips of vials (e.g., injection molded strips) may beeither in a strips of 8 or 12 vials, conforming to industry standardformats, which allows the strips to be expanded to 96-vial and/or384-vial formats, if desired.

The inventive micro-vial design allows small consumption of DNA products(gDNA) to be sample for quality control prior to qPCR or SangerSequencing analysis, or for post-PCR sample analysis using capillaryelectrophoresis-based DNA fragment analyzers.

The inventive micro-vial design provides flexibility for automatedsample injection in CGE based instruments.

The inventive micro-vial design provides robust and reproducible sampleinjections, resulting in accurate analysis results with betterintegrity.

While the invention has been particularly shown and described withreference to the preferred embodiments, it will be understood by thoseskilled in the art that various changes in form and detail may be madewithout departing from the spirit, scope, and teaching of the invention.Accordingly, the disclosed invention is to be considered merely asillustrative and limited in scope only as specified in the appendedclaims.

We claim:
 1. A vial for holding a micro-volume of fluid, comprising: abody defining an interior wall, the wall comprising a cylindrical samplesection having a bottom, a wider cylindrical alignment section, aconical guide section, and a relatively large cylindrical body sectionhaving an opening, arranged in sequence in that order along a centeraxis of the body.
 2. The vial as in claim 1, wherein the sample sectionhas a cylindrical section that is sized to receive a tip of a capillarytube and to hold a micro-volume of fluid.
 3. The vial as in claim 2,wherein the cylindrical section of the sample section has an internaldiameter of about 0.5 mm, receiving the tip of the capillary tube havingan outside diameter of similar size.
 4. The vial as in claim 1, whereinthe micro-volume is in the order of less than 5 micro-liters.
 5. Thevial as in claim 4, wherein the micro-volume is in the order of 1 to 2micro liters.
 6. The vial as in claim 2, wherein the alignment sectionhas a larger diameter than the sample section, sized to receive acylindrical support that coaxially supports the capillary tube.
 7. Thevial as in claim 6, wherein the cylindrical support is a tube, throughwhich the capillary tube extends with the tip beyond an end of the tubeto dip into the micro-volume of fluid held in the sample section.
 8. Thevial as in claim 7, wherein the conical guide section provides a taperedwall surface to guide the capillary tube and the support tube into thealignment section and the tip of the capillary tube into the samplesection.
 9. The vial as in claim 8, wherein the body section has thelargest diameter compared to the other sections of the body, forcontaining a relatively large volume of fluid.
 10. The vial as in claim9, wherein the body is injection molded plastic.
 11. A strip of vialsfor holding micro-volumes of fluid, comprising a plurality of N (N>0)vials in which adjacent vials are connected by a tab, each vial having astructure as in claim
 1. 12. The strip of vials as in claim 11, whereinN is equal to 8 or 12.